High frequency power combiner/divider
View Patent ↗Radio frequency (RF) power amplifiers are provided which may include high power, wideband, microwave or millimeter-wave solid state power amplifiers based on waveguide power combiner/dividers.
1. A waveguide power combiner/divider for operation at a selected wavelength, comprising:
a plurality of hollow waveguides having a hollow core configured to support at least one radiation mode therein, the waveguides having first and second ends with the second ends in communication with one another to permit communication of radiation modes therebetween;
a plurality of transmission line waveguides having a center conductor transmission line disposed therein, each of the transmission line waveguides having an electromagnetic end launcher operably connected to respective first ends of the hollow waveguides, each electromagnetic end launcher having an elongated center conductor end portion that extends into the hollow core of the hollow waveguide; and
a plurality of ground posts each disposed at a respective end launcher in electrical communication with the center conductor and a wall of the hollow waveguide, respectively, to ground the end launcher to the hollow waveguide wall.
2. The waveguide combiner/divider according to claim 1 , wherein the second ends of the hollow waveguides are conjoined at a port having a waveguide base wall, the port comprising a conductive base mounted to the base wall and comprising a transmission line in electrical communication with the base, the transmission line configured to permit RF communication between the at least one radiation mode of the hollow waveguides and an RF signal in the transmission line.
3. The waveguide combiner/divider according to claim 1 , wherein the transmission line waveguides comprise a coax structure.
4. The waveguide combiner/divider according to claim 1 , wherein the elongated center conductor end portion has a distal end and wherein the ground post is disposed inward from the distal end to provide an overhang portion of the end portion.
5. The waveguide combiner/divider according to claim 1 , wherein one or more of the hollow waveguides, transmission line waveguides, and ground posts comprises a layered structure comprising a plurality of layers.
6. The waveguide combiner/divider according to claim 5 , wherein the plurality of layers of at least one of the hollow waveguides, transmission line waveguides, and ground posts comprise the same material.
7. The waveguide combiner/divider according to claim 1 , wherein the plurality of transmission line waveguides comprises two transmission line waveguides operably connected to a respective first end of one of the hollow waveguides.
8. The waveguide combiner/divider according to claim 1 , wherein the sum of the length of the elongated center conductor end portion and the height of the respective ground post is about ¼ of the selected wavelength.
9. The waveguide combiner/divider according to claim 1 , wherein the hollow waveguides are coplanar to one another and wherein a longitudinal axis of the elongated center conductor is parallel to the coplanar plane of the hollow waveguides.
10. A solid state power amplifier, comprising:
a waveguide power combiner/divider having a plurality of waveguide input ports;
a plurality of monolithic microwave integrated circuit chips each in electrical communication with a respective input port of the waveguide power combiner/divider; and
a plurality of port isolation circuits disposed between the monolithic microwave integrated circuit chips and the waveguide power combiner/divider input ports to provide isolation among input ports of the waveguide power combiner/divider.
11. A solid state power amplifier according to claim 10 , wherein the port isolation circuits comprise one or more of a Gysel or Wilkinson.
12. A solid state power amplifier according to claim 10 , wherein the waveguide power combiner/divider comprises:
a plurality of hollow waveguides having a hollow core configured to support at least one radiation mode therein, the waveguides having first and second ends with the second ends in communication with one another to permit communication of radiation modes therebetween;
a plurality of transmission line waveguides having a center conductor transmission line disposed therein, each of the transmission line waveguides having an electromagnetic end launcher operably connected to respective first ends of the hollow waveguides, each electromagnetic end launcher having an elongated center conductor end portion that extends into the hollow core of the hollow waveguide; and
a plurality of ground posts each disposed at a respective end launcher in electrical communication with the center conductor and a wall of the hollow waveguide, respectively, to ground the end launcher to the hollow waveguide wall.
13. A method of forming a waveguide combiner/divider by a sequential build process, comprising:
depositing a plurality of layers, wherein the layers comprise one or more of a conductive material, a sacrificial photoresist material, and a non-conductive material, thereby forming a structure, comprising:
a plurality of hollow waveguides having a hollow core configured to support at least one radiation mode therein, the waveguides having first and second ends with the second ends in communication with one another to permit communication of radiation modes therebetween;
a plurality of transmission line waveguides having a center conductor transmission line disposed therein, each of the transmission line waveguides having an electromagnetic end launcher operably connected to respective first ends of the hollow waveguides, each electromagnetic end launcher having an elongated center conductor end portion that extends into the hollow core of the hollow waveguide; and
a plurality of ground posts each disposed at a respective end launcher in electrical communication with the center conductor and a wall of the hollow waveguide, respectively, to ground the end launcher to the hollow waveguide wall; and
removing the sacrificial photoresist.
14. The method according to claim 13 , wherein the second ends of the hollow waveguides are conjoined at a port having a waveguide base wall, the port comprising a conductive base mounted to the base wall and comprising a transmission line in electrical communication with the base, the transmission line configured to permit RF communication between the at least one radiation mode of the hollow waveguides and an RF signal in the transmission line.
15. The method according to claim 13 , wherein the transmission line waveguides comprise a coax structure.
16. The method according to claim 13 , wherein the elongated center conductor end portion has a distal end and wherein the ground post is disposed inward from the distal end to provide an overhang portion of the end portion.
17. The method according to claim 13 , wherein the sequential build process comprises depositing a plurality of stacked layers and one or more of the hollow waveguides, transmission line waveguides, and ground posts comprises a layered structure comprising the stacked layers.